Some brakes do more harm than good, even some very expensive ones.
Skip long brakes with narrow passages and complex bleeding patterns that do nothing for you.
This is what I look for on a brake:
-Short
-Light
-2 sets of wide ports. 3 is ok as soon as it doesn't add too much weight and length.
-Plenty of bleeding with large ports on a logical pattern.
-flush with crown or close to flush in the first chamber. Can quickly clean debris w/o need to dismount.
AI and Badger makes the most efficient brakes but they are expensive.
You can get the similar results from a Hollands quick discharge.
Holland's Quick Discharge Muzzle Brake 5/8-28 Thread SS
PRI is also a great performer for folks on a budget..
PRI Muzzle Brake Quiet Control 5/8-24 Thread AR-10 LR-308 Steel Matte
The brand doesn't matter as soon as it is well cut with the proper dimensions. Avoid baffle walls wider than the caliber shot
and specially any passages narrower than the caliber diameter + 0.20. Concentricity is key and make sure that is well
indexed and locked so it will not walk on you.
I think in Ebay one might find some at a good price with decent dimensions but I also see a lot of garbage with cuts
and patterns that do not make any sense. They look cool that is what many folks are looking for.
Ideally if one can have the threads cut to the widest possible section and a brake to match and the passage cut to the proper
caliber dimension to get the most out of that brake, that would be perfect. But the most important thing is, even
if one doesn't get the most performance, one should avoid certain designs that actually interfere with the accuracy
potential of the rifle.
The best possible patterns today do not differ much from the best ones designed after 1900. The physics involved
continue to be the same.